I think this is extrodinary: Copyright Milos Stefanek, 1999. "ON VISUALISATION, CONCENTRATION & MEDITATION."

Whatever I remembered from that little Czech booklet on Meditation, I started to practice. I selected a small a dot, a little black speck on the wall and I kept looking at that dot, in a standing position, for hours. Clearing my mind, concentrating on my breathing, thinking of nothing. There was nothing else to do nowhere to go I had the whole day to practice my meditation. I stood there in my cell for hours, concentrating on my breathing, looking at that dot. The only interruptions to my practice were when the meals were served to the prisoners, or when I was called for Gestapo interrogations. As soon as I was back in my cell, I resumed my practice of meditation. The other interruption was when the guards were calling in the corridors "Hof", which was the daily yard walk for a few minutes, then back to the cells and back to my meditation. The other interruption was, when three times a week a Gestapo man came to the prison, to collect me for interrogation." Click on image to read whole essay.